Jagat Singh Chauhan and Chandra Kishor Singh of Uttarakhand's Banbasa town have been recuperating at a hospital in Bhimdutta municipality.
Chauhan and Singh themselves informed the police at the Gaudachauki Police Post after yesterday's incident.
Bikram Nath and Karan Bhandari have been detained, Kanchanpur Superintendent of Police Prakash Chand said.
The incident occurred when the victims were returning from a casino at night.
"Bhandari was riding a bike while Nath opened fire on the Indians when they did not stop during a chase," he said.